Krebs on Security

In-depth security news and investigation

Posts Tagged: hotmail

Expect phishers and other password thieves to up their game in 2016: Both Google and Yahoo! are taking steps to kill off the password as we know it.

New authentication methods now offered by Yahoo! and to a beta group of Google users let customers log in just by supplying their email address, and then responding to a notification sent to their mobile device.

According to TechCrunch, Google is giving select Gmail users a password-free means of signing in. It uses a “push” notification sent to your phone that then opens an app where you approve the log-in.

The article says the service Google is experimenting with will let users sign in without entering a password, but that people can continue to use their typed password if they choose. It also says Google may still ask for your password as an additional security measure if it notices anything unusual about a login attempt.

The new authentication feature being tested by some Gmail users comes on the heels of a similar service Yahoo! debuted in October 2015. That offering, called “on-demand passwords,” will text users a random four-character code (the ones I saw were all uppercase letters) that needs to be entered into a browser or mobile device.

This is not Yahoo!’s first stab at two-factor authentication. Another security feature it has offered for years — called “two-step verification” — sends a security code to your phone when you log in from new devices, but only after you supply your password. Yahoo! users who wish to take advantage of the passwords-free, on-demand password feature will need to disable two-step verification for on-demand passwords to work.

The success of social networking community Twitter has given rise to an entire shadow economy that peddles dummy Twitter accounts by the thousands, primarily to spammers, scammers and malware purveyors. But new research on identifying bogus accounts has helped Twitter to drastically deplete the stockpile of existing accounts for sale, and holds the promise of driving up costs for both vendors of these shady services and their customers.

Image: Twitterbot.info

Twitter prohibits the sale and auto-creation of accounts, and the company routinely suspends accounts created in violation of that policy. But according to researchers from George Mason University, the International Computer Science Institute and the University of California, Berkeley, Twittertraditionally has done so only after these fraudulent accounts have been used to spam and attack legitimate Twitter users.

Seeking more reliable methods of detecting auto-created accounts before they can be used for abuse, the researchers approached Twitter last year for the company’s blessing to purchase credentials from a variety of Twitter account merchants. Permission granted, the researchers spent more than $5,000 over ten months buying accounts from at least 27 different underground sellers.

In a report to be presented at the USENIX security conference in Washington, D.C. today, the research team details its experience in purchasing more than 121,000 fraudulent Twitter accounts of varying age and quality, at prices ranging from $10 to $200 per one thousand accounts.

The research team quickly discovered that nearly all fraudulent Twitter account merchants employ a range of countermeasures to evade the technical hurdles that Twitter erects to stymie the automated creation of new accounts.

“Our findings show that merchants thoroughly understand Twitter’s existing defenses against automated registration, and as a result can generate thousands of accounts with little disruption in availability or instability in pricing,” the paper reads. “We determine that merchants can provide thousands of accounts within 24 hours at a price of $0.02 – $0.10 per account.”

SPENDING MONEY TO MAKE MONEY

For example, to fulfill orders for fraudulent Twitter accounts, merchants typically pay third-party services to help solve those squiggly-letter CAPTCHA challenges. I’ve written here and here about these virtual sweatshops, which rely on low-paid workers in China, India and Eastern Europe who earn pennies per hour deciphering the puzzles.

The Twitter account sellers also must verify new accounts with unique email addresses, and they tend to rely on services that sell cheap, auto-created inboxes at Hotmail, Yahoo and Mail.ru, the researchers found. “The failure of email confirmation as a barrier directly stems from pervasive account abuse tied to web mail providers,” the team wrote. “60 percent of the accounts were created with Hotmail, followed by yahoo.com and mail.ru.”

Bulk-created accounts at these Webmail providers are among the cheapest of the free email providers, probably because they lack additional account creation verification mechanisms required by competitors like Google, which relies on phone verification. Compare the prices at this bulk email merchant: 1,000 Yahoo accounts can be had for $10 (1 cent per account), and the same number Hotmail accounts go for $12. In contrast, it costs $200 to buy 1,000 Gmail accounts.

Finally, the researchers discovered that Twitter account merchants very often spread their new account registrations across thousands of Internet addresses to avoid Twitter’s IP address blacklisting and throttling. They concluded that some of the larger account sellers have access to large botnets of hacked PCs that can be used as proxies during the registration process.

“Our analysis leads us to believe that account merchants either own or rent access to thousands of compromised hosts to evade IP defenses,” the researchers wrote.

Damon McCoy, an assistant professor of computer science at GMU and one of the authors of the study, said the top sources of the proxy IP addresses were computers in developing countries like India, Ukraine, Thailand, Mexico and Vietnam. “These are countries where the price to buy installs [installations of malware that turns PCs into bots] is relatively low,” McCoy said.

One of the most-viewed stories on this site is a blog post+graphic that I put together last year to illustrate the ways that bad guys can monetize hacked computers. But just as folks who don’t bank online or store sensitive data on their PCs often have trouble understanding why someone would want to hack into their systems, many people do not fully realize how much they have invested in their email accounts until those accounts are in the hands of cyber thieves.

This post aims to raise awareness about the street value of a hacked email account, as well as all of the people, personal data, and resources that are put at risk when users neglect to properly safeguard their inboxes.

Sign up with any service online, and it will almost certainly require you to supply an email address. In nearly all cases, the person who is in control of that address can reset the password of any associated services or accounts –merely by requesting a password reset email.

Your email account may be worth far more than you imagine.

How much are these associated accounts worth? There isn’t exactly a central exchange for hacked accounts in the cybercrime underground, but recent price lists posted by several miscreants who traffic in non-financial compromised accounts offer some insights.

One prominent credential seller in the underground peddles iTunes accounts for $8, and Fedex.com, Continental.com and United.com accounts for USD $6. Groupon.com accounts fetch $5, while $4 buys hacked credentials at registrar and hosting provider Godaddy.com, as well as wireless providers Att.com, Sprint.com, Verizonwireless.com, and Tmobile.com. Active accounts at Facebook and Twitter retail for just $2.50 apiece.

As I’ve noted in previous stories, some crime shops go even lower with their prices for hacked accounts, charging between $1 to $3 for active accounts at dell.com, overstock.com, walmart.com, tesco.com, bestbuy.com and target.com, to name just a few.

Even if your email isn’t tied to online merchants, it is probably connected to other accounts you care about. Hacked email accounts are not only used to blast junk messages: They are harvested for the email addresses of your contacts, who can then be inundated with malware spam and phishing attacks. Those same contacts may even receive a message claiming you are stranded, penniless in some foreign country and asking them to wire money somewhere.